in my fact table, there are 2 columns - disaster_type_A, and disaster_type_B
(The reason why i have 2 columns is because a record might be in one or both
of the types).

i create a dimension table called dim_disaster, and want to link to
disaster_type_A and disaster_type_B, of course as you know, this wouldn't
work. so i keep the link between dim_disaster and disaster_type_A, then
create a nother dimesion(dim_disaster_B) based on the same data in
dim_disaster and link to disaster_type_B. But the problem is when i try to
add the new dimenstion in the fact's editor, since the 2 dimesions using the
same table, it only displays one dimension... anybody can give me some
suggestions or solutions... thanks.

Create a view on the dim table in SQL Server (or what ever relational
source you are using) and use the view as the source for the second
dimension.

--
Regards
Darren Gosbell [MCSD]
<dgosbell_at_yahoo_dot_com>
Blog: http://www.geekswithblogs.net/darrengosbell